Arsenal manager Arsene Wenger says striker Olivier Giroud has improved "tremendously" since making the switch from Montpellier.
The 28-year-old struggled to make an impact during his early days at Arsenal but is today one of the key men in the Frenchman's line-up.
"I believe that he is a different player today than the guy who arrived here for two reasons," Wenger said after Sunday's 2-0 win.
"One, he understands what top-level football demands, works with a great concentration in training and he has improved tremendously on his mobility, his technical quality and of course his body is very strong. He uses it very well.
"The first goal [against Middlesbrough] is what we try to do in our game and our build-up.
"The second goal shows that the game belongs to the players as well because it's a consequence of two players who respond quickly to a situation, analyse it quickly and do what they want to do well.
"That's basically what it was. It's a consequence of intelligence and technique."
The Gunners were delighted to welcome Alexis Sanchez back in the starting line-up against Middlesbrough in the FA Cup and the 65-year-old says the Chilean is finally back to full fitness.
"He had a good performance," Wenger said.
"I think he became stronger as the game went on but because I took a gamble with him, I took him off with 20 minutes to go. He needed the game as well.
"He always wants to play. Everybody's like that but he's a bit more like that.
"He didn't miss too many games and what was important for him was to get through the game without injury."
